16 Mr. Fnirholme on the Falls of Niagara 



about 100 feet; and this softer substance, being acted upon 

 by constant moisture and a violent current both of air and of 

 water, is rapidly decomposed, and gradually leaves the harder 

 beds overhanging their base to the amount of 50 or 60 feet. 

 This excavating effect produces that species of gallery into 

 which the more intrepid visitors can enter for about 150 feet, 

 and in front of which the appalling cataract tumbles like an 

 agitated curtain. It is clear that this excavating effect cannot 

 be carried on beyond a certain point; for when the upper 

 strata are, at length, no longer able to sustain their mighty 

 load of waters, the whole table rock must give way, and a si- 

 milar process be again renewed. By such incessant action, 

 the form of the cataract is constantly changing. Many in- 

 stances have occurred of late years; and in 1828 a fragment 

 of rock gave way, and was carried into the abyss, which was 

 calculated at not less than 5000 cubic yards, producing re- 

 peated shocks as of an earthquake, which were felt to a con- 

 siderable distance in the surrounding country*. 



The receding of this remarkable waterfall being thus esta- 

 blished, both by the evidence of facts and by the very nature 

 of the case itself, the question at once arises as to the length 

 of time required for executing the seven miles which have al- 

 ready been completed-, and it is a self-evident fact, that how- 

 ever long or short this period may be found to be, it must have 

 commenced at zero; or, in other words, the commencement 

 of this great natural work must distinctly point out the com- 

 mencement of the present system of things on the whole conti- 

 nent of North America ; and, by reasonable analogy, in other 



* " The epithet of the horse-shoe" says a recent traveller, " is no longer 

 applicable to the greater fall. In the progress of those changes which are 

 continually taking place from the attrition^ of the cataract, it has assumed a 

 form which 1 should describe as that of a semihexagon." — Men and Man- 

 ners in America, vol. ii. p. 320. 



** Nothing which enters the awful cauldron of the fall is ever seen to 

 emerge from it. Of three gun-boats which were sent over the falls some 

 years after the termination of the war, one fragment only, about a foot in 

 length, ever was discovered. It was found at Kingston, about a month 

 after the descent of the vessels." — Ibid. p. 328. 



The author of u Transatlantic Sketches" says, "The American fall 

 seems fast assuming the horse-shoe form. In standing under the falls, one 

 constantly hears the sound of falling rocks amidst the awful roar of the 

 cataract ; but many of these may have been rolled down the rapids from a 

 distance, and may not be portions of the rock of the cascade itself." 

 Vol. ii. p. 155. — This, indeed, is highly probable; but at the same time, 

 every falling stone at this cataract, even from the rapids above, tends to 

 forward the great natural section which we are now considering. None 

 come from Lake Erie, nor from the smooth course of the river for 12 or 14 

 miles below that lake; and there must obviously always be a rapid in pre- 

 paration above the fall, and retrograding along with it. 



